Since the discovery of the carbon nanotube, its application to electronic semiconductors, electronic devices, or other fields has been strongly expected, and various studies have been carried out by a large number of researchers.
Among the carbon nanotubes, for example, a single-wall carbon nanotube has a shape with a piece of a graphite sheet comprising a six membered ring of carbons rolled like a cylinder. Depending on the rolling style of the graphite sheet, that is, the diameter of the carbon nanotube and the chirality (helical degree), the conductivity of the carbon nanotube differs completely so as to provide a metal or a semiconductor.
However, according to the production method for carbon nanotubes so far, the diameters or the chiralities of the carbon nanotubes to be produced cannot be controlled so that only inhomogeneous ones can be obtained, and thus the difference of the conductivity of the carbon nanotubes provided by the diameters or the chiralities has not been utilized sufficiently.
In contrast, recently, it was revealed that the chemical reaction can be promoted by the light irradiation. These days, it was also found out that the Flahren's reaction is carried out by the assistance of the light excitation. In view of these facts, it is considered that the light irradiation has a possibility to have any influence on the chemical reaction of the single-wall carbon nanotubes (SWNTs), however, the influence to the chemical reaction of the single-wall carbon nanotubes by the light irradiation has been completely unknown so far.
Then, in view of the above-mentioned circumstances, the present invention has been achieved, and its object is to provide a method for selectively obtaining carbon nanotubes, capable of solving the problems of the conventional technique, having structures different from the structures of the carbon nanotubes to be lysed by selectively combusting and lysing carbon nanotubes of specific structures.